Atlantis rollover and launch targets remain tight

Both the rollover of Atlantis and her March 15 launch date will “go down to the wire” according to shuttle manager Wayne Hale, following a number of issues that arose during the rollout review this week.

Hale noted that if NASA has to delay the launch of STS-117 by a couple of days to ensure everything is right on Atlantis, “then so be it.”

At present, Atlantis is heading towards an early morning rollover on February 7 for the short trip to the Vehicle Assembly Building (VAB). Once inside the giant building, Atlantis will be mated with ET-124 and the twin Solid Rocket Boosters. Rollout to launch pad 39A is expected one week later.

While that is still the target – ahead of the NET (No Earlier Than) March 15 launch date – critical paths remain on ensuring Atlantis’ Thermal Protection System (TPS) is ready for flight, along with issues of duplicate seal serial numbers, plus a need to clarify if a chip off the GOX 2-inch disconnect could be an ignition source, which are among a number of concerns.

‘Still working towards rollover on 7th. Tile is still the critical path. Orbiter discussing Chit (note of problem) on ceramic inserts,’ noted the minutes of the shuttle standup/integration report, which Wayne Hale chaired. ‘Have a lot of work to do, which will get us down to the wire. But, plan right now is to be ready to go to the OPF on Saturday. Will roll at 6:00 a.m. on Wednesday.’

The issues with tile inserts are related to a missing insert on Discovery, noticed during post flight processing in OPF 3 (Orbiter Processing Facility). The missing insert was noticed to be absent from one of her engine dome heat shields, following the removal of her three SSMEs (Space Shuttle Main Engines) recently.

NASA, Boeing and United Space Alliance engineers have noticed that other inserts appear to be loose, with the requirement to move forward with replacing some of Atlantis’ inserts, before checking their bonding – including those around the windows on the orbiter – once Atlantis arrives at the launch pad.

‘We had a missing tile insert after the last flight of OV-103 (Discovery on STS-116. It was on one of the engine dome heat shield rings. We looked around that ring to see if there is any more that appear to be loose. Found two more that are loose. Those two were also right next to two other tiles where we replaced loose inserts before the flight,’ noted the standup report.

‘It says that something is wrong with the installations. Those four happened to be installed on the same day in February 2004. Believe something going on with recent installations since we started to notice more missing or loose inserts lately. Went back to February 2003 and looked at all the inserts that have been installed on OV-104 (Atlantis) since then.

‘There are a number of them on the base heat shield that we want to replace now, because of the suspect condition. There are 12 on the lower surface that we want to go pull and test to see how they are doing. The rationale on the lower surface is still good; we think we are less likely to lose them there, because they are thicker tiles that give you more surface area for bonding.

‘Nonetheless, we would like to pull on those inserts and ensure that they really are bonding in there well. As soon as we get access at the pad, we would like to look at the inserts around the windows to ensure they are tight.’

Also noted on the standup is an issue that arose when checking the seals that had been installed on to the orbiters. While there isn’t any specific note of which areas of the orbiter are in question with the seals. engineers have found that duplicate part numbers were seen both in stock and on the vehicle.

‘An issue came up this week on Tuesday. Were working a problem on MPTA (Main Propulsion Test Article) seals that might have been installed on the fleet. (We) wanted to ensure we knew the history and the pedigree of those seals,’ the report added. ‘Able to clear that problem and do not actually have MPTA seals installed the fleet, but in the course of doing that and trying to clear that problem, we encountered another problem.

‘We have duplicate part numbers in logistics where it says we have the seal in stock and also have same seal according to CBAT system installed on the vehicle; obviously, that cannot be. So, makes us question what really is installed in the vehicle. We are trying to run that down. For OV-104 (Atlantis), there were four of these seals with duplicate part numbers. We need to determine what are the real seals that were installed on the vehicle and what are the real ones that are on the shelf.’

On the ignition concern relating to a chip that came off the GOX 2-inch disconnect – not specified, but believed to be from STS-116 – NASA are hopeful that historical data will close this potential hazard issue, in order to avoid an unknown amount of additional work on the area between the External Tank and the orbiter’s belly.

‘(The program feels) comfortable with it, but there is a chrome chip that came off of the poppet. Threat there is whether this chip could be an ignition hazard in the GOX system if another chip was to come off and make its way downstream. There was a similar occurrence on a different disconnect that happened in 1999. A lot of testing was done at WSTF (White Sands Test Facility); we were able to clear that condition. We are pulling all the data from that previous occurrence to see how it relates to this one.

‘Do not know the final outcome of that until everyone has a chance to work through that. If everyone is comfortable with previous testing, then can go ahead and sign off on that (issue); otherwise, there will be additional work, which is unknown.’

Other issues were also listed in depth including torque checks on carrier panels being required before Atlantis is allowed to rollover to the VAB, and a need to ensure engineering changes at a contractor that provides pumps and hydraulics pose no impact or threats to potential problems with their parts in the APU (Auxiliary Power Unit) and hydraulics systems.

While the checking of such fine details are very much commonplace in ensuring the safety of the orbiter fleet, Hale made sure everyone was aware that this will always come before launch schedule.

‘We have to get all of this right, and if we have to delay the flight a couple of days to ensure that (for instance) the panel is torqued the right way, than so be it. This is not one of the things that we would want to push the schedule on. Want to get good resolution on all of these issues.

‘We all want to fly on March 15th, but these are the kinds of things we want to get right. Thank you for your diligence. We will hear about them at the Orbiter Rollout Review and FRR (Flight Readiness Review) as well.’

Hale also emphasised this point when referring to last week’s memorials of the loss of both Challenger and Columbia, adding ‘everyone should go back to their jobs and think about what we do, which is flying highly complex vehicles in very unforgiving environments at the edge of what is technologically capable at this time in history and doing it well.’

While processing on both Discovery and Endeavour are progressing to plan, the recent bad weather in the area has caused some issues with the launch pad that will carry out all of the remaining shuttle launches, Pad 39A.

‘Have had quite a bit of rain at KSC. On Pad A, discovered some water intrusion in the PCR (Payload Checkout Room),’ added the standup. ‘Looking at that and performing an assessment. On Monday, will make a determination about payload to the pad, which will happen either on 12th or the 18th; will be looking at that over the weekend.’

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